Advances in orthodontics as in general dentistry, have led to a realization in recent times that effective treatment need not be segmented in the mouth of the patient. General dentists have progressed from the stage of filling only one tooth per patient appointment through mouth quadrant dentistry to full mouth reconstruction in appropriate cases. Similarly, in orthodontics, it has been discovered that effective treatment, in fact, greatly improved treatment results are obtainable through application of the appropriate forces to teeth of the entire dental arch simultaneously, rather than selective and progressive application of forces as has been the past practice. It has also been discovered that with proper patient cooperation the traditional rest periods between applications of pressure to the teeth can be dispensed with. If there is no physiological barrier to consistent pressure being used, it should be used to the fullest in order to accomplish the best results in optimum time. Also, the use of consistent pressure without periods of interruption and the application of pressure to the teeth of the full dental arch has recently been found to induce better cellular response and hence a more effective movement of the teeth.
In light of the above knowledge, the present invention has been devised to improve the application of consistent pressure to the teeth in the full dental arch to accelerate orthodontic treatment of patients and to increase the effectiveness of the treatment. In furtherance of these objectives, a compound curve orthodontic arch wire is provided by the invention which can progressively distribute forces to the teeth in the dental arch from the molars in the posterior to the incisors in the anterior. By means of the invention, each tooth can have an equal pressure applied to it as contrasted to straight wire arches with a large tip-back, where comparatively great pressure may be applied to molars and substantially no pressure applied to the anterior teeth.
By means of the invention, consistent pressure is applied simultaneously to all of the teeth in the dental arch, as where the anterior teeth require intrusion. The functioning of the compound curve arch wire embodying the present invention takes advantage of simple mechanics by utilizing moderate forces applied through comparatively long lever arms. It is important that the teeth under pressure have freedom to move with minimum friction in the orthodontic appliance, and one of the prime freatures of the invention is to reduce friction to the absolute minimum obtainable as a practical matter. A further ability of the invention is that the gentle pressure applied to the teeth at the start is not reduced abruptly as the necessary movement of teeth takes place. The gentle pressure consistently applied at the start and throughout the movement process enables cellular action to occur within the periodontial membrane, where the blood supply is adequate to carry away the product of osteoclasts.
The orthodontic arch wire according to the invention is pre-looped, as with a pair of spaced loops, for space closure or maintaining spaces closed during treatment. Thus, it can be seen that a very simple, unitary pre-formed wire appliance can function simultaneously in several different ways to enhance and accelerate orthodontic treatment for the benefit of both patient and orthodontist, economically and in terms of convenience. The many advantages of the invention over prior art practice should be apparent to those skilled in the art.
Some examples of the known patented prior art are contained in U.S. Pat. Nos. 1,638,006; 2,556,414, 2,582,230 and 3,994,068.